Very recently, various sorts of imaging subjects are photographed by employing, for instance, portable telephone terminals equipped with cameras, digital cameras, digital video cameras, and the like, so that media data containing still images, moving pictures, voice information, and so on can be produced in a simple manner. Also, acquired media data may be easily distributed by utilizing electronic mails, or may be readily distributed via servers present on the Internet.
On the other hand, when media data have been acquired by photographing imaging subjects including persons, since personal information is contained in the media data, privacy problems may occur. For example, there are many possibilities that a specific person who has been photographically taken in a photograph has a desire that this photograph is not wanted to be viewed by any persons other than herself. As a consequence, if media data containing photographs and the like flow out with respect to a third party and/or on the Internet, then the photograph of the specific person may be viewed by the third party, so that her privacy of the specific person may be intruded.
However, for instance, even in such a case that media data containing a photograph is transferred from a photographer with respect to a specific person photographically taken in this photograph based upon a formal procedure, if servers provided on the Internet and electronic mails are utilized so as to transfer the media data, then there are some possibilities that the media data may flow out via the Internet with respect to a third party. As a consequence, in the case that such a media data is transferred via the Internet, the following idea is desirably required: That is, in this idea, after the media data is encrypted, the encrypted media data is transferred via the Internet; and even when the media data flows out with respect to a third party, the third party cannot view the photograph of the media data.
For instance, in a technical idea disclosed in a patent publication 1, the automatic photographing apparatus produces the client ID every photographing operation, and transfers the produced client IDs to the photographed persons (clients). In this case, the photographed persons can access the servers by utilizing the received client IDs so as to view the relevant photographs. However, since a third party who does not know the client IDs cannot view the photographs, privacy can be protected.
Also, in a technical idea disclosed in a patent publication 2, such a technical idea has been proposed. That is, an image is automatically transmitted via a mail with respect to a specific person specified based upon faces of persons contained in images acquired by photographing operations.
Patent Publication 1: JP-A-2004-54672
Patent publication 2: JP-A-2005-267146